In general, window curtains are used in buildings for shielding sunlight and protecting the private things. Moreover, the window curtains also have the effects of beautifying the environment.
In a general window curtain, curtain cloth slides along a sliding track for opening and closing the window curtains. The sliding operation is primarily induced from the rolling wheels on the top edge of the window curtain and the rolling wheels roll along a sliding track. Moreover, the movement of the rolling wheel is guided by a guide block.
Referring now to FIG. 6, the guide block (1) of prior art comprises the following components:
A pulling plate (11): A toggle (111) is on the upper portion of the pulling plate (11). A hanging plate (112) is on the lower rim of the toggle (111). A hanging hole (113) is on the distal end of the hanging plate (112) for being hooked by the hanging pin on the upper portion of the window curtain (3) A left rib (114) and a right resisting plate (115) are installed on the inner rims of the left and right end surfaces of the toggle (111) of the hanging plate (112).
A left wheel seat (12): a left spacer (121) with a through hole on the center thereof is the primary body. The left spacer (121) has an outer diameter slightly larger than the inner diameter of the left ribs (114) of the toggle (111). One side of the left spacer (121) is extended to form a convex tube (122). Another side of the left spacer (121) is extended to form a left rolling wheel (123). The left side of convex tube (122) on the left wheel seat (12) is inserted into the hole (116) of the toggle (111). The left spacer (121) is enforced into the left rim (114) by the elastic property thereof for combining the pulling plate (11).
A plurality of rolling balls (13): The rolling balls (13) are located above the left spacer (121) ofthe outer rim of the convex tube (122) on the left wheel seat (12).
A right wheel seat (14): the right spacer (141) with a through hole on the center thereof is the primary body of the right wheel seat (14). The outer diameter of the right spacer (141) is slightly larger than the inner diameter of the right resisting plate (115) of the toggle (111). One side of the right spacer (141) is extended to form as a convex tube (142). The outer diameter of the convex tube (142) is slight smaller than the inner diameter of the convex tube (122) of the left wheel seat (12). Another side of the right spacer (141) is extended as a right rolling wheel (143).
The convex tube (142) of the right wheel seat (14) is inserted into the hole (116) of the toggle (111) through the right side of the toggle (11). The right spacer (141) is enforced into the inside of the right rib (115) for combining a pulling plate (11). The convex tube (142) of the right wheel seat (14) is exactly inserted into the inner rim of the convex tube (122) of the left wheel seat (12) for combining the left wheel seat (12).
By the rolling of the rolling balls (13), the rotations of the left and right rolling wheels (123) and (143) becomes more smooth and the friction in rotation can be reduced.
However, the prior art design still has the following disadvantages:
1. The friction and collision between two rolling balls (3) occurs as the rolling ball is rolling. This will induce the wearing of the rolling balls. PA1 2. The rotation of the rolling ball is retarded. PA1 3. As the rolling balls (3) collide with one another, noises will generate. PA1 4. Although the convex tube (142) of the right wheel seat (14) is enforced into the inner rim of the convex tube (122) of the left wheel seat (12) for combining the left wheel seat (12), However, this combination still depends upon the character of the materials, therefore, the stability thereof is insufficient. PA1 5. A left rib (114) and a resisting plate (115) are extended from the inner rim of the left and right end surfaces of the pulling plate (11) so that after the left and right spacer (121) and (141) of the left and right wheel seat (12) and (14) enter into the ring hole (117) of the pulling plate (11), the gap therebetween is too large, thus, the left and right spacers (121) and (141) easily loosen.